Dental impression tray



Dec. 21 1926. I 1,611,152

J. C. BACKUS DENTAL IMPRESSI 0N TRAY Filed June 4, 1925 10 a. aac u /s.

v 7 I gmmrm Patented Dec. 21, 192 6. It

JOHN, cLAr'roN Backus, or siv n'rnr'onr, Pnn svLvANIA;

DENTAL nurnnssron 'rni ivf j" I Application ina rune-1i, 1925f seriaruo; 24,910.

V This invention relates. to: dentalimpression tra'y'sand has as its; general object to providea tray which .will. overcome the disadvantages attending the-use of the ordinaryimpression trays; In the use of the ordinary tray; when the. materiahinfwhich the impressionis made, sets and hardens, a partial vacuum 'is'formed between the surface of the material .andJtheroof of the patients month and, considerableforce is frequently. required to loosen the tray,-thereby causing :annoyance'a'nd pain to the patient and frequently resulting in the impression being so v is slidablyadjustably-fitted a vent plug hav distorted that the plate molded in accord ance therewith 'will not properly fit the patients mouth. Therefore, the presentinvention contemplates the provision'of a tray embodying means-whereby this partial vacuum maybe destroyed so that the tray and the material therein may bedislodged. and removed from the patients month without causing any discomfort and without any likelihoodofdistorting the impression.

The trayembodying' the invention is provided in its bottom with a socket into which ing the lower end of its bore in communication with the socket a'tube being mount edbeneath the tray and in communication at its forward end with the said socket so that air may be admitted through the tube and I through the' bore of the plug to" destroy the partial vacuum-formed and thus per-- .Init of ready dislodgment-of the tray and the material therein after the impression] has been taken, and the invention contemplates the provision, at the upper end of said plug of a valve which will close the upper end of the bore of the plug at the time the impression :is taken so' that the desired vacuum may be created. v In the accompanying drawlngsz' it Figure 1 is a plan viewof the tray emg bodyingthe invention. Y c

Figure 2 is a vertical longitudinal sectional view through the tray. Y F igure3 is a perspective view-illustrating a slight modification of the invention.

In the drawings, the tray is-indicated in general by the numeralylo and comprises the usual bottom 2 andmarginal upstanding wall 3, both of which are formed to conform more or less to the contour ofthe roof of the mouth, and the bottom 2 of the tray is formed, upon, its under side, with a thickened portion 4 provided with a cylindrical tion within the cavity of the tray.

socket having, an? opening Gforinedfin the forward.wallfthereof. :A handle "7 "extends forwardly from the wall 3 of thetrayand upon the-under rsideofthe handle 7 at :"the forward end thereof an'dhasfiits rearend v fitted into theopening V6, so, thatthe-bore of 95 the tube is placed in communication ivith the lower end of the socket -5, thefor'\vard end i s/preferably; of; the; shape shown in the drawings,'and an; air supply tube 8' of metal I isfitted throughia'sleeve portion 9.- provided of the tube eXtending a short distance' beyond the forward end of the handle 7 Y The-ventplug heretofore referred to, is

indicated in general by the numeral *10 and the plug bodyris formed of softrubber and" includesa cylindrical shankiportion 11 provided at'its upper end with acircumscribmg outstanding flange 12 so that the upper end 7 of theplug is of somewhat greater-diameter than the body of the plug. A metal sleeve 13 is fitted onto the plugbodyll with-its lower endflush with the lower end of'said 1 body and its upper end engaging. the under side of the flange 12, and the sleeve is slidposition its upper side at the desired eleva In order that the desired vacuum may be created and maintained while the impression is being taken, the soft rubber pluglO is provided with an integral circular valve flap 14: integrally connected with the flange 12 at, onesidethereof; as indicated-byI-the numeral 1,5, cheHsaid flap being relatively thin andnormally resting fiat upon the up-' ,per end of theplug body and itsflange, as

shown infull lines inFigure 2 of the drawings, and thus closing the upper end ofjthe bore of the plug, which bore is indicated by the numeral 16; r y p i In the use of the tray; the plug 10 is ad the plastic'material in which the impression is to be-Inade is packed into the'tray and about thevalve andthe under side of the flange 12 thereof. 7 The tray is then inserted in the usual'manner andisipressed against the roof of the mouth to make the impression in the material in the tray, and the surface of the material will, of course, be depressed to conform to the shape of the roof 10 being forced downwardly into the material until the upper side of'the valve 14 is y ably frictionally fitted in tothe socket 5, so that the plug may be vertically adjusted to justed to. a suitably elevated position and 0 of the mouth and the upper gums, the plug flush with the-uppersurface-of the material. Inasmuchias the plug 10..is-of .soft rubber,

it will yield when it contacts the roof of the mouth and, therefore, no inconvenience will be experienced'bythe patient. Afterthe impression has been made, the tray is permitted to remain in place until the material has set and hardened, whereupon. fair is forced through the tube 8 into v the socket and through the bore 16 of the plug 10, thus causing the valve 1 1 to open sufliciently to providerfor the admission of air between the rootof the patients mouth and'the sur face ofthe material; in which theimpression has been made, thereby destroying: the partial vacuum which was formed during 1 the setting of theinater1al. .and permitting of the ready withdrawalof: the" tray without the use ofgforce or causing any inconvenience: to the patient. r V

The sleeve 13 serves to suitably stiffen the upper'portion "of thebody 11 of the vent plug IOso that the fiange at the upper end ofthe plug cannot become-materially distorted atthe time the impression is taken and, furthermore, the tube, being of metal,

provides for greater freedom of sliding movement ofthe'plug body in the socket 5.

In order to obviate the necessityitorf holding thevent plug in the elevated position shown in "Figure-:2,- while the plastic-"ma teria'lis being'filled into the tray, :a light helical spring 16 is arranged within the lower portion of the socketfrand bearsat its a lower end against the bottom-01" the socket mand-supportsthe said vent plug 10 in the position illustrated, it being understood that when'the impression is made, the plug may move downwardly into'the socket a greater or-less' distance under the pressure I exerted thereagainst.

As illustrated in. Figure 3 of the drawings, instead of providing the plug body :withan-integral' flap valve such as the valve 7 14, a small; valveidisc 17 in the nature of a GJ'CUlflI' PIBCB Qf tough, thin paper having the same diameter-as the top of .theplug body, may-be employed, this disc being moistened prior totmaklng the impression andlaid fiat upon thei upper side of the 2. A dental impression tray having: La.

socket in its bottom, means-ford admitting described the invention, a

air under pressure into the lower portion of the socket, a vent-plug'slidablyadjustably fitted :into the upper portion of the-socket and extendin above the-:upper surfacei'of the bottom or the tray,"the said plug being of rubber and having a bore, and a valve flap integral with the lp lugsat itsgupper-end and normally seating 'uponsaid-end to -close the upper end of the bore of the plug,i:the'

said flap being: adapted tov open upwardly when air under pressure is: admitted into the socket.

3. A dental impression trayv having a socket in its bottom, means"fork admitting air under pressure ll'ltOKlZhG'-SOCkQt, t vent plug comprising a body of soft rubber of substantially cylindrical form having a bore, a sleeve iittedupon the saidebody and' slidably 1 tting Within the: socket, the-said body having an outstanding flange at its upper-end, and a valveflap integral with the flange at one'side and normally resting upon the upper end ot the plugaiid closing theupper end of the bore therein, theflap being adapted to openupwardly when air underpressure is admitted into the socket.

1. A. dental impression trayqhavin'g 1 a socket in its-bottom, means' for admitting comprising; :an impe'rforate' disc like relatively thin body arranged upon the upper end of-the vent plug and closing the bore.

In testimony, whereof I afiix mysignature.

JOHN CLAYTON BAGKU S. -'-[L. s.]

air under pressure into the-socket a vent plug slidably fitted into the socket and having a bore, and a valve for'closing the bore 

